Ante-Nicene Fathers, Vol III:
Tertullian: Part II: In What Sense Flesh and Blood are Excluded from the Kingdom of God.

Chapter L.—In What Sense Flesh and Blood are Excluded from the Kingdom of God.

Putting aside, however, all interpretations of this sort, which criminate the works of the flesh and blood, it may be permitted me to claim for the resurrection these very substances, understood in none other than their natural sense. For it is not the resurrection that is directly denied to flesh and blood, but the kingdom of God, which is incidental to 7651
the resurrection (for there is a resurrection of judgment 7652
also); and there is even a confirmation of the general resurrection of the flesh, whenever a special one is excepted. Now, when it is clearly stated what the condition is to which the resurrection does not lead, it is understood what that is to which it does lead; and, therefore, whilst it is in consideration of mens merits that a difference is made in their resurrection by their conduct in the flesh, and not by the substance thereof, it is evident even from this, that flesh and blood are excluded from the kingdom of God in respect of their sin, not of their substance; and although in respect of their natural condition 7653
they will rise again for the judgment, because they rise not for the kingdom. Again, I will say, “Flesh and blood cannot inherit the kingdom of God;” 7654
and justly (does the apostle declare this of them, considered) alone and in themselves, in order to show that the Spirit is still needed (to qualify them) for the kingdom. 7655
For it is “the Spirit that quickeneth” us for the kingdom of God; “the flesh profiteth nothing.” 7656
There is, however, something else which can be profitable thereunto, that is, the Spirit; and through the Spirit, the works also of the Spirit. Flesh and blood, therefore, must in every case rise again, equally, in their proper quality. But they to whom it is granted to enter the kingdom of God, will have to put on the power of an incorruptible and immortal life; for without this, or before they are able to obtain it, they cannot enter into the kingdom of God. With good reason, then, flesh and blood, as we have already said, by themselves fail to p. 584obtain the kingdom of God. But inasmuch as “this corruptible (that is, the flesh) must put on incorruption, and this mortal (that is, the blood) must put on immortality,” 7657
by the change which is to follow the resurrection, it will, for the best of reasons, happen that flesh and blood, after that change and investiture, 7658
will become able to inherit the kingdom of God—but not without the resurrection. Some will have it, that by the phrase “flesh and blood,” because of its rite of circumcision, Judaism is meant, which is itself too alienated from the kingdom of God, as being accounted “the old or former conversation,” and as being designated by this title in another passage of the apostle also, who, “when it pleased God to reveal to him His Son, to preach Him amongst the heathen, immediately conferred not with flesh and blood,” as he writes to the Galatians, 7659
(meaning by the phrase) the circumcision, that is to say, Judaism.